This invention relates to a tilt cab-over-engine (C.O.E.) truck of the kind in which the cab is pivotally connected to the truck chassis for forward tilting about a cab pivot axis to provide access to the engine and radiator area. It relates particularly to a grille system for a tilt cab truck.
In the design of a tilt cab-over-engine truck it is desirable to maintain a minimum cab length and reasonable cab height while offering the maximum driver space possible. A clean appearing vehicle is also an important consideration.
To obtain a minimum cab length it is necessary to locate the cab directly over the engine and radiator with the engine and radiator as far forward under the cab as possible, practically right to the front of the cab. With this style of cab the driver position is above and to one side of the engine and radiator area.
In order to maintain reasonable cab height, the engine and radiator area extends up into the middle of the cab and is normally covered (in the cab up or driving position) by a cab tunnel which runs through the cab and goes over the radiator and engine. Since the cab tilts forward, the cab tunnel needs to be wide enough to clear the radiator. To provide maximum space within the cab for the driver, and possibly a passenger, the width of the cab tunnel needs to be kept to a minimum. With the radiator being wider than the engine, the cab tunnel width can be reduced after it clears the radiator area to provide adequate space to locate the driver and passenger.
The length of the radiator tunnel (the portion of the cab tunnel covering the radiator area) can be reduced and thus the intrusion of the radiator tunnel into the cab seating area and gear shifting area can be minimized by using a relatively high cab pivot. That is, a low cab pivot requires more swing of the cab to go past the radiator (and thus a longer cab tunnel) while a higher cab pivot requires less swing of the cab and therefore permits a shorter radiator tunnel.
When the cab pivot is raised sufficiently high as to permit the desired short length of radiator tunnel, the axis of the cab pivot is located above the bottom of the cab and up behind the grille. When the grille is designed so that the lower edge aligns with the bottom edge of the cab, the lower part of the grille extends down below the cab pivot axis. As a result, when the cab is tilted, the grille either has to move away from the cab or has to be split into two pieces so that the lower part of the grille does not swing back into the radiator.
The cab front also extends down below the pivot axis to minimize the gap above the bumper. The cab front can remain a singular structure without hinging or splitting the areas below the pivot axis, if an opening in the cab front is made wider than the truck chassis and its components. The lower cab front can then tilt rearwardly without interference. This opening should be covered by the grille and therefore establishes the grille width.